Electrode clamp



1953 w. E. MOORE 2,647,936

ELECTRODE CLAMP Filed April 12, 1949 2 Sheets-Sheet l JNVENTOR. WILLIAME. MOORE.

F A'ITORNEYS.

Aug. 4, 1953 w, MOORE 2,647,936

ELECTRODE CLAMP Filed April 12, 1949 2 Sheets-Sheet 2 INVENTOR. j]WILLIAM E. MOORE.

ATTORNEYS.

Patented Aug. 4, 1953 UNITED STATES PATENT OFFICE 2,547,936 I ELECTRODECLAMP William Enoch Moore, Pittsburgh, Pa., assignor to DelawareEngineering Corporation, Pittsburgh, Pa., a corporation of DelawareApplication April 12, 1949, Serial No. 86,989

5 Claims.

1 V This invention relates to an electrode clamp, and more particularlyto one that is useful for electric arc smelting furnaces. Thisapplication is a continuation-impart of my application, Se rial No.653,271, filed March 9, 1946, and entitled Electrode Clamp, now UnitedStates Letters Patent No. 2,477,077, issued July 26, 1949.

Electrodes of relatively large size, and electrodes having a diameter ofabout fifty (50) inches are not unusual, and are commonly used inelectric arc type smelting furnaces. Such electric furnaces aregenerally of two types, the closed top type which includes a refractoryroof, and the open top type. The heatfrom an electric arc furnace isquite intense, and particularly is this true in the open top typefurnace'such as carbide and ferro-alloy furnaces, wherein the electrodeclamp which surrounds and supports the electrode is subjected to severeradiant heat and abuse from charging material as well as from chargingand stoking tools.

Considerable difiiculty has been encountered in electrode clampconstructions for sizable electric smelting furnaces, particularlyinsofar as obtaining suitable electrical contact between the electrodesupporting means or clamp and the electrode so as to enable transmissionof the neoessarily high electric current from the supporting means orclamp into the electrode without fusing or burning at the points ofcontact. Another difficulty has been that of cooling the electrode clampor supporting structure as Well as the electrode so as to withstand theabnormal heating effects of the furnace.

The electrode clamp of my invention includes a sufficient number ofadjustable segments or contact shoes so as to make proper electricalcontact with the electrode to satisfactorily transmit the necessaryelectric current from the clamp into the electrode, and to insure goodcontact even though the electrode may vary (usually from 2% to 4%) indiameter. The shoes are water cooled, and are made of high electricalconducting material.

The contact shoes and fixedly attached connector pipes useful in a largefurnace are necessarily quite heavy, and since the shoes must be changedat intervals it is highly desirable to so attach the connector pipes tothe bus pipes that connections both for electric power and cooling watercan be made and broken in a minimum of time, at the same timeremembering that the connections must have high electric conductivityand possess strength. Difficulty has been experienced in making suchconnections, and my inthe third function is to conduct electricity fromthe bus pipes to the shoes. vIt is highly desirable, that the connectorpipes be secured to "the bus pipes by readily disconnectable couplingsor clamps, which afford adequate support for the connectors andconnected contact shoes, and also provide good electrical connectionbetween the connector pipes and bus pipes while at the same time theconnector pipes are secured to the bus pipe in water conductingrelationship.

The bus pipes from which I suspend my contact shoes, by means ofconnector pipes, are electrically connected in multiple and are arrangedto extend from a point reasonably distant from the electrode,tosubstantially surround the electrode and be radially spaced from theelectrode. The two bus pipesvertically spaced apart must conduct coolingwater under pressure from a distant point to and from the connectorpipes, and also supplya highly conductive path to the connectors forconduction of the electric current to which, in turn is conductedthrough the connector pipes, to and through the contact shoes and fromthem to the electrode. I make the bus pipes preferably from strong wallcopper tubing.

It is an object of my invention to provide an electrode clamp for an arcfurnace, which clamp includes a plurality of contact shoes which willclosely embrace the electrode and which shoes are relatively flexibly.connected to supporting Another obiectof my inventionis to provide anelectrode clamp which has spaced watercooled contact shoes whichareconnected to bus pipes by relatively laterally flexible connectors whichare both water conductors and electric. conductors, and which arereadily disconnectably clamped to the bus pipes.

A further object of my invention is to provide a novel bus pipeconnection for furnishingelectric current as wellras cooling fluid to aplurality of contact shoes disposed about the periphery of an arcelectrode, and at the same time serve as supporting means for suspendingsuch shoes in a manner that the shoes may be moved or collapsed radiallyinwardly to the electrode. The contact shoes bein connected to the buspipe by means which are readily disconnectable from the bus pipes.

A still further object of my invention is to provide an arrangementwhereby bus pipes may supply cooling water and electricity to electrodecontact shoes connected to the bus pipes by connector pipes which pipesare secured to the bus pipes by a secure but simple make and break orsplit clamp which will ensure good electric conduction and waterconnections.

Other objects and advantages of my invention will become apparent from astudy of the follow ing specification and the accompanying drawingswherein I have shown the preferred embodiment of my invention. V

In the drawings:

Figure 1 is a top or plan view of a liquid cooled bus pipe constructionembodying my invention, and which supplies electrical current andcooling liquid to a plurality of contact shoes clamped to an arc furnaceelectrode;

Figure 2 is a side view of the structure shown in Fig, 1 which clearlyillustrates a plurality of clamped contact shoes suspended from buspipes by means of connector pipes;

Figure 3 is a view along the line III-III of Figure l, but to anenlarged scale showing a side View of the clamping means;

Figure 4 is a view along the line IVIV of Figure 1, but to an enlargedscale, and showing a vertical end view of the clamping means;

Figure 5 is a top plan view of the clamping means shown in Figure 4;

Figure 6 is an enlarged view of the connection at the top of theconnector pipes, and

Figure 7 is a view partly in section along the line VII-VII of Figure 2,but to an enlarged scale showing the connections to the bus pipes.

The electrode clamp according to my invention, in its broadest aspects,is made up of a sufficient number of adjustable segments or contactshoes to provide a flexible clamp giving very good electrical andphysical contact with the electrode, which shoes are water cooled toprevent overheating, and are made of suitable electrically conductivematerial. The contact shoes are suspended from suitable bus pipes byconnector pipes which connector pipes are firmly secured to the buspipes by clamping means so that the connector pipes are readilydisconnectable from the bus pipes. The connector pipes carry coolingwater to and from the contact shoes as well as conduct electric power tothe shoes.

Referring more particularly to the drawings, numeral 3 denotes some of aplurality of segments or contact shoes disposed in spaced relationshiparound the periphery of an arc electrode E of an electric furnace. Theshoes are made of suitable electric conducting material, such as copper,and each has a circuitous passage therein through which cooling watermay be passed to eifectively cool the shoe. Each shoe has two radiallyprojecting horizontal flanges 4 and 5 which are spaced vertically so asto fit above and below, respectively, the links 6 of a flexible chain orclamp '1 extending in a circle surrounding and in contact with the outerfaces of the shoes. The chain may be tightened to urge the contact shoesradiall inwardly against the electrode by means of appropriate nuts andbolts 8 and 9 received at diametrically opposite portions of the chain.The chain links are preferably made of 4. non-magnetic material, such asaustenitic or non-magnetic alloy steel.

Each contact shoe is provided at the sides of the bottom withhorizontall and circumferentially projecting lugs l0 cast integrallywith the shoe. Each lug has an opening which is the end of thecircuitous passage formed in the contact shoe.

The electrode clamp includes two electrically conductive water cooledbus pipes II and I2 both of which extend from a point distanct from theelectrode in parallel straight portions [3 and I4, and each has aportion I5 and [6 respectively, substantially annular, whichsubstantially surround or embrace the electrode E so as to leave a spacebetween the annular portion and the electrode. I prefer to make the buspipes of suit able double extra strong copper tubing since the bus pipesconduct electric current to the clamp as well as conduct water. Thestraight portions of the bus pipes are joined by vertical metal bracesI1, and by horizontal metal braces l8. These braces strengthen the buspipe construction, and connect the bus pipes in multiple and thus insuregood electrical conduction in the bus pipe system.

The contact shoes are spaced below the bus pipes and are suspendedtherefrom by connector pipes or down pipes 20 and 2| which are formedfrom suitable copper tubing and serve to support the contact shoes whileat the same time they conduct electricity from the bus pipes to thecontact shoes as well as carry cooling water to and from the contactshoes.

Since the contactshoes 3 are arranged to allow radial movement so thatthey may be forced into close engagement with the surface of theelectrode E by tightening the chain 1 by manipulation of nuts and bolts8 and 9, or may be released from engagement by the loosening of the nutsand bolts 8 and 9, it is necessary that the connector pipes 20 and 21 besomewhat flexible laterally to permit such movement. The connector pipesor drop pipes 20 and 2| are of substantially less diameter than the buspipes, and are of such length as to allow the desired flexibility. Thelower ends of the connector pipes 20 and 2| are received in the lugs H3and are securely fastened thereto as by screwing and/or welding so thatthe passages in the connector pipes 20 and 2|, and the openings in thelugs ID are in register so as to permit the flow of cooling Water frombus pipe H down through the connector pipe 20 through the contact shoe3, and thence upwardly through the connector pipe 25 to the bus pipe l2as indicated by the arrows in Figure '2.

It is highly desirable that the connector pipes be secured to the buspipes in very good electrical contact, and in water conductingrelationship as well as in shoe supporting relationship. According to myinvention, I provide such function performing connections which arereadily connectable and disconnectable so that any contact shoe or shoesmay be readily disconnected from or secured to the bus pipes in a veryshort time, and in a very satisfactory manner. Such an arrangement is ofgreat value in the operation of a furnace.

Each of the connector pipes 20 and 2| is formed at the upper end into aline parallel to the axis of the electrode and is secured to the buspipes H and I2 by means or split bolted clamps 30, of electricallyconductive material, there being one clamp for each contact shoe 3.These clamps are particularly well shown in ass sts 7 Figures 3-, 4, and5. The clamp consists or a contact'block 3| and a olainping'plate 32which isbolted to the contact block.

The contact block 3| is formed in generally rectangular shape. Theback'of the block as a centrally disposed transverse partial rib 33, andtwo transverse grooves 34 and 35 arcuately shaped to receive the buspipes II and I211 sp'e'ctively in closely fitted engagement. The rib 33is disposed between theadjoining bus pipes and serves 'to join the buspipes in spaced relationship thus contributing to the stability of thebus pipe arrangement. The front of the block 3| has two longitudinalgrooves 36 and 37 for close engagement with the upper ends of theconnector pipes. The contact blocks 3| are brazed or Welded to the buspipes H and 12 at appropriate locations, there being one clamp for eachcontact shoe.

.The clamp. plate 32 generally rectangular in shape has two parallelgrooves 38 and 39 for closely engaging the upper end portionsof theconnector pipes. Suitable bolt holes 40 in block 3| register withcorresponding bolt holes 4! in plate '32. Bolts 42 with suitable nutspass through holes 40 and 4| and serve to bind the clamping plate 32 andcontact block 3| into tight clamping engagement with the upper endportions of the connector pipes. I

Suitable tubes or conduits 43 are provided for conducting cooling fluidfrom the bus pipe H tothe top of the connector pipes-2o. Thse'tubes havea readily detachable connection 44 to the bus pipe II and a readilydetachable pipe connection or union 45 to the top of the connector pipes20. Likewise the connector pipes 2| are connected to the bus pipe I2 byconduits or tubes 46 having a detachable connection 41 to the bus pipe[2 and a detachable connection or union 48 with the top of connectorpipes 2|. The top of each connector pipe has a nut 49 threadedlyadjustable on the end of the connector p p which when seated restsagainst the top of contact block 3|, and serves to position theconnector pipes relative to the contact block, and also insures thatthere will be no accidental slippage between connector pipes and thecontact block when the clamps are loosened.

By this arrangement of clamps and associated tubes, an electrode shoe 3may be readily disconnected by loosening the clamp at the bus pipes anduncoupling the water tubes 43 and 46, after which the shoe may bedropped from engagement with the collapsing chain 4.

The bus pipes are preferably fitted at their ends remote from theelectrode with electrical contact wings or fins such as 50, 5|, and 52to which flexible cable connections such as 3 (only one being shown) maybe removably attached for supplying electric current to the bus pipes.

The electrode and its clamping structure are supported by support loops54 and 55 preferably of non-magnetic material, which loops encircle thebus pipes H and I2 and are connected at their tops by a supporting plate56 which may be moved vertically by any suitable operating hoistmechanisms (not shown) all of which is well-known in the art. A supportloop 57 of non-magnetic material is connected to the fin bearing ends ofbus pipes H and I2. Suitable hose nipples 53 and 59 are connected to theends of the bus pipes H and 12 respectively and serve as inlets andoutlets respectively for cooling water.

I l'iave provided an iiicient electrode clamp for use' in electric arcfurnaces which cramps have a substantial degree of-flexibility thusproviding extremely good contact with the electrode so as to avoidburning, pitting, and the like: furthermore, fl have prtn'ided anefficiently cooled "supporting and current carrying clamping "structurethat is able to withstand deleterioii'seffects norma ly cause'd'by theintense heat and gases of the furnace, and a structure whichii'ibodi'e's *init's construction contact shoes and associated co'j-e'ewr pipes which are secured to the bus l pipes by 'ieadnydisconnectable clamping means whisper ing means are novel.

While I-have illustrated and described a cerpresent preferre'd specificembodiment of my invention it will 'be-understood'that this is by way ofillustration only; and that various changes and i modifications may bemade within the contemplation er my -'invention and within tli 'es'c'opeofthe following claims.

man

i. For use in adjustable electrode ramp for an electrode in an electricarc furnace ineluding a plurality of electrically Conductive shoesarranged in spaced "circumferential relation around theelectrodepapluralityof flexible connector pipes connected at the lowerends to said shoes for conducting electric power and water totlie shoes'and 'for' suspendi g said shoes n n mute-ter ace power conduct nestspipes embracing the electrode at a distance above the shoes, theinvention which comprises means for clamping the upper ends of theconnector p pes to the bus pipes, said means including a contact blockin fixed electrical contact with the bus pipes, and a clamp plate boltedto the contact block, the block and plate being disposed to clamp theupper ends of the connector pipes between them.

2. For use in an adjustable electrode clamp for an electrode in anelectric arc furnace including a plurality of electrically conductiveshoes arranged in spaced circumferential relation around the electrode,a plurality of flexible connector pipes connected at the lower ends tosaid shoes for conducting electric power and water to the shoes and forsuspending said shoes from two water and power conducting bus pipesembracing the electrode at a distance above the shoes, the inventionwhich comprises means for clamping the upper ends of the connector pipesto the bus pipes, said means including a contact block in fixedelectrical contact with the bus pipes, a clamp plate bolted to thecontact block, the block and plate being disposed to clamp the upperends of the connector pipes between them, and water conduits extendingfrom the upper ends of the connector pipes to the bus pipes.

3. An adjustable electrode clamp for an electrode in an electric arcfurnace comprising a plurality of electrically conductive shoes arrangedin spaced circumferential relation around the electrode, a plurality offlexible connector pipes connected at the lower ends to said shoes forconducting electric power and water to the shoes and for suspending saidshoes from two water and power conducting bus pipes embracing theelectrode at a distance above the shoes, means for clamping the upperends of the connector pipes to the bus pipes, said means including acontact block in fixed electrical contact with the bus pipes, a clampplate bolted to the contact block, the block and plate being disposed toclamp the upper ends of the connector pipes between them, and readilydisconnectable water conduits connecting the upper ends of the connectorpipes to the bus pipes in water conducting relationship. v

4. For use in an adjustable electrode clamp for an electrode in anelectric arc furnace including a plurality of electrically conductiveshoes arranged in spaced circumferential relation around the electrode,a plurality of flexible connector pipes connected at the lower ends tosaid shoes for conducting electric power and water to the shoes and forsuspending said shoes from two water and power conducting bus pipesembracing the electrode at a distance above the shoes, the inventionwhich comprises means for clamping the upper ends of the connector pipesto the bus pipes, said means including a contact block in fixedelectrical contact with the bus pipes, a clamp plate bolted to thecontact block, the block and plate being disposed to clamp the upperends of the connector pipes between them, readily disconnectable waterconduits connecting the upper ends of the connector pipes to the buspipes in water conducting relationship, and means at the top of theconnector pipes for positioning the connector pipes in vertical positionrelative to the contact block.

5. For use in an adjustable electrode clamp for an electrode in anelectric arc furnace including a plurality of electrically conductiveshoes arranged in spaced circumferential relation around the electrode,a plurality of flexible connector pipes connected at the lower ends tosaid shoes for conducting electric power and water to the shoes andforsuspending said shoes from two water and power conducting bus pipesembracing the electrode at a distance above the shoes, the inventionwhich comprises a contact block in fixed electrical contact with the buspipes, and a clamp plate mounted in operative clamping position withrespect to said block, the block and plate being disposed to clamp theupper ends of the connector pipes between them to thereby provide anelectrical connection through said contact block for said connectorpipes with said bus pipes.

WILLIAM ENOCH MOORE.

References Cited in the file of this patent UNITED STATES PATENTSSwitzerland Mar. 15, 1943

